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T: Fachverband Teilchenphysik
T 29: QCD 3
T 29.6: Talk
Thursday, March 12, 2009, 18:05–18:20, A017
Measurements of differential jet cross sections in Z/γ*+jets+X events at D0, Tevatron — •Henrik Nilsen and Ralf Bernhard — Abt. Prof. Dr. Karl Jakobs, Physikalisches Institut, Hermann-Herder-Str.3, D-79104 Freiburg
The production of jets in association with vector bosons is an important process in quantum chromodynamics (QCD) and is a significant source of background in many standard model measurements and in searches for physics beyond the standard model. In this talk we present new measurements in the Z(→ ee)+jets channel from D0, Tevatron. The measured cross sections are presented in bins of the transverse momentum of the Nth jet in events containing at least 1, 2, and 3 jets. Comparisons are made using predictions from next-to-leading-order and leading-order perturbative QCD from mcfm as well as several commonly used event generators. In particular it is investigated to what extent the differential distributions for the higher jet multiplicities can be described by parton-shower-based event generators like pythia and herwig and how they compare to event generator predictions where matrix element and parton shower merging procedures are adopted, like in alpgen and sherpa. For the latter ones the ambiguities in choice of factorization and renormalization scales are used to tune the generators to achieve an improved description of the measurements.